Microsoft Wireless Intellimouse Explorer with Tilt Wheel - Night Vision (M03-00061) Designed by ergonomic experts for your comfort Longer battery life -- many users average more than 6 months battery life All five buttons, including the wheel button, can be easily reprogrammed to perform popular commands in your favorite applications Wireless -- no mouse cord or recharging station Delivers up to four times the performance of other optical mouse devices, giving you precise cursor movement and unmatched responsiveness